It is common for the wearer of eye glasses to use a strap which is secured to each temple bar of the glasses so that the strap resides behind the head and neck of the wearer as the glasses are worn. Thus, the glasses may be worn in athletic events or just normal wear with less risk of loss.
Typically, such straps comprise a strap member made of woven cord or the like in which the strap member defines at each end a loop. Each strap member loop engages a flexible temple bar loop, which is typically made of flexible plastic material. The plastic temple bar loop is intended to fit about the ends of the temple bars, and then to be secured thereto by a sliding member which tightens a retention loop about the glasses temple bar, to secure each end of the strap to a temple bar.
The strap may be so constructed by known selection of material properties and dimensions that the sliding member tends to hold the retention loop about the temple bar in tightly retaining state, so that the strap remains secured to the glasses until one positively slides the sliding member to enlarge the retention loop, and thus to remove the temple bars of the glasses from their secured relationship.
As one disadvantage of prior art straps for glasses as described above, when they are not in use it is possible for the sliding member to slide completely off of the temple bar loop and be lost. When this happens, the glasses straps of the prior art become substantially useless, since they can no longer be tightly retained to the temple bars of eye glasses.